diff --git a/modules/luci-mod-system/htdocs/luci-static/resources/view/system/flash.js b/modules/luci-mod-system/htdocs/luci-static/resources/view/system/flash.js
index c1e1273772..4a1058d0d9 100644
--- a/modules/luci-mod-system/htdocs/luci-static/resources/view/system/flash.js
+++ b/modules/luci-mod-system/htdocs/luci-static/resources/view/system/flash.js
@@ -426,7 +426,7 @@ return view.extend({
 						E('button', {
 							'class': 'cbi-button cbi-button-save',
 							'click': ui.createHandlerFn(view, 'handleBackupSave', this.map),
-							'disabled': isReadonlyView
+							'disabled': isReadonlyView || null
 						}, [ _('Save') ])
 					]));